Riemann曲面上的正常和拟正常复合算子

Riemann曲面M上的平方可测1-形式全体和解析1-形式全体均可构成Hilbert空间。本文讨论Riemann曲面上的解析映射导出的这类Hilbert空间上的复合算子,研究复合算子的正常性、拟正常性的诱导映射特征。特别地,当M有有限三角剖分时,证明了正常复合算子、拟正常复合算子、酉复合算子、等距复合算子和可逆复合算子等价。

H^3(-c^2)中的CMC-c曲面

讨论了对称空间SL(n,C)/SU(n)中的曲面.首先,讨论了H3(-c2)中的CMC-c曲面(常中曲率为c的曲面)与R3中的极小曲面的关系,利用初等方法证明了H3(-c2)中的一个CMC-c曲面族,当c趋于零时,收敛到R3中的一个极小曲面的结论;其次,把经典的Ricci定理推广到对称空间SL(n,C)/SU(n)上.证明了单连通黎曼曲面(M2,ds2)可以共形等距地浸入到SL(n,C)/SU(n)上,且有全纯右Gauss映射的充分必要条件是ds2的截面曲率K<0及Ricci条件——-K.ds2的截面曲率为+1.

零理想边界的素端上某类椭圆型方程的非负解

考虑具有零理想边界的非紧镶边Ｒｉｅｍａｎｎ曲面Ω＝Ω∪ Ω及其上的Ｄｉｒｉｃｈｌｅｔ积分有限的非负局部Ｈｏｌｄｅｒ连续的二重共变量Ｐ．用Ｆ表示方程上Δｕ＝Ｐｕ在 Ω取极限值０的非负连续解全体．本文讨论拟Ｐｉｃａｒｄ原理成立的充要条件并证明：若Ω的每一理想边界点都有端邻域满足广义Ｈｅｉｎｓ条件，则Ｍａｒｔｉｎ函数全体所成之集是Ｆ中的极小正解全体所支撑的子半线性空间Ｐ的一个Ｈａｍｅｌ基，而且Ｆ可表示为与Ｐ相关的直和形式．

二维向量丛的最大子线丛

本文中我们利用 Ａ．Ｂｅｒｔｒａｍ和 Ｂ． Ｆｅｉｂｅｒｇ证明的在 ｇ＝５的当 Ｓ（Ｅ）＜２时的一般代数曲线上二维特殊稳定向量丛的存在定理作为反例，说明进一步的Ｍａｒｕｙａｍａ猜想和Ａｒｒｏｎｄｏ－Ｓｏｌｓ猜想在ｇ＝５的一般代数曲线上均不能成立．

关于Teichmüller空间中一个问题的注记(英文)

本文指出了Ara Basmajian在美国数学会出版的“Contemporary Mathematics”第221 卷中提出的一个关于Teichmuller空间的问题的答案是完全否定的.

Submanifolds with Parallel Mean Curvacture

In this paper, we consider a class of submanifolds with parallel mean curvacture vector fields. We obitain the suffitient conditions that the above submanifolds is of tatall umbilical and that its codimension is decrease.

C~∞ Compactness for a Class of Riemannian Manifolds with Parallel Ricci Curvature

In this paper we prove that tile set of Riemannian manifolds with parallel Ricci curvature, lower bounds for sectional curvature and injectivity radius and a upper bound for volume is coo compact in Gromov-Hausdroff topology. As an application we also prove a pinching result which states that a Ricci flat manifold is flat under certain conditions.

On the Tangent Bundle of a Hypersurface in a Riemannian Manifold

Let （Mn, g） and （N^n＋1, G） be Riemannian manifolds. Let TMn and TN^n＋1 be the associated tangent bundles. Let f ： （M^n, g） → （N^＋1, G） be an isometrical immersion with g = f^＊G, F = （f, df） ： （TM^n,g） → （TN^n＋1, Gs） be the isometrical immersion with g= F＊Gs where （df）x ： TxM → Tf（x）N for any x∈ M is the differential map, and Gs be the Sasaki metric on TN induced from G. This paper deals with the geometry of TM^n as a submanifold of TN^n＋1 by the moving frame method. The authors firstly study the extrinsic geometry of TMn in TN^n＋1. Then the integrability of the induced almost complex structure of TM is discussed.

《The Real and the Complex》的书评

我们通常所说的高等微积分中大部分基本的公式和技巧是在18世纪发展起来的.更仔细的定义,更严格的证明,没有这些证明难以得到的微妙新结果,以及由此提出的新概念,则是19世纪的产物.19世纪也是复分析基础的来源,从Cauchy-Riemann(柯西-黎曼)方程到Riemann曲面以及其他成果.如果你想知道这一切怎么得来的,你应该去读一下Jeremy Gray的《实分析和复分析(The Real and the Complex)》这本书.

Hyperbolic Mapping Classes and Their Lifts on the Bers Fiber Space

Let S be a Riemann surface with genus p and n punctures. Assume that 3p- 3 ＋ n 〉 0 and n 〉 1. Let a be a puncture of S and let S = S∪{α}. Then all mapping classes in the mapping class group Mods that fixes the puncture a can be projected to mapping classes of Mod$ under the forgetful map. In this paper the author studies the mapping classes in Mods that can be projected to a given hyperbolic mapping class in Mode.

VARIATIONAL PROPERTIES OF THE INTEGRATED MEAN CURVATURES OF TUBES IN SYMMETRIC SPACES

Let Pt denote the tubular hypersurface of radius t around a given compatible submanifold in a symmetric space of arbitrary rank. The authors will obtain some relations between the integrated mean curvatures of P, and their derivatives with respect to f. Moreover, the authors will emphasize the differences between the results obtained for rank one and arbitrary rank symmetric spaces.

MINIMAL SURFACES IN 3-DIMENSIONAL SOLVABLE LIE GROUPS

The author studies minimal surfaces in 3-dimensional solvable Lie groups with left invariantRiemannian metrics. A Weierstraβ type integral representation formula for minimal surfaces isobtained.